On to a sand-coloured floor, browned at the perimeter as if scorched by newly dead fires, strides the god Dionysus (divinely embodied by Jotham Annan, in flowing robes and leaf-spiked locks). On this simplest of settings unfolds one of the most unsettling plays of Europe's past two-and-a-half millennia. Euripides's exploration of the nature of human existence intertwines man with god, male with female, animal with human, sanity with madness. The plot sounds ridiculous. Dionysus disguised as his own priest persuades his blasphemous, unbelieving cousin Pentheus to dress as a woman (Sam Alexander delicately transforms from strutting masculine to undulating feminine) and spy on the sacred rites. Discovered, Pentheus is torn to pieces by his mother who, in bacchic frenzy, mistakes him for a lion. The play, however, is sublime and Braham Murray's taut production (shabby-chic chorus aside) does it justice, especially in John Kirk and Terence Wilton's transcendent messengers' speeches. Riveting.